assume cs:codesg, ds:datasg, ss:stacksg
datasg segment
    db 'ibm .   .   .   ';16byte
    db 'dec .   .   .   '
    db 'dos .   .   .   '
    db 'vax .   .   .   '
datasg ends
stacksg segment
    db '0 0 0 0 0 0 0 0'
stacksg ends
codesg segment
    start:  mov ax, datasg
            mov ds, ax
            mov ax, stacksg
            mov ss, ax
            mov sp, 8

            mov bx, 0; 控制行
            
            
            mov cx, 4; 控制外层循环 行循环
        s:  push cx
            mov si, 0; 控制列
            mov cx, 3

        s0: mov al, [bx+si]
            and al, 11011111B
            mov [bx+si], al
            inc si
            loop s0
            
            add bx, 16
            pop cx
            loop s

            mov ax, 4c00H
            int 21H
codesg ends
end start
